NSAIDs (anti-inflammatory painkillers like ibuprofen, diclofenac, and naproxen) are the first-line pain medication for kidney stones. They outperform opioids because they directly target the source of the pain: swelling and spasm in the ureter, the narrow tube connecting your kidney to your bladder. Major urology guidelines, including those from the European Association of Urology, recommend an NSAID as the first drug of choice for acute stone pain.
Why NSAIDs Work Better Than Opioids
Kidney stone pain happens when a stone gets stuck in the ureter, triggering inflammation and muscle spasm that raises pressure in the kidney. NSAIDs block the chemical signals (prostaglandins) that drive this inflammation, which means they address the root cause rather than just masking the sensation. Opioids like morphine only dull the pain signal in your brain without reducing the swelling that creates it.
A pooled analysis of multiple clinical trials found that patients given NSAIDs achieved greater pain score reductions than those given opioids. They were also 25% less likely to need a second dose of rescue medication. Side effects tell an even clearer story: only about 6% of patients on NSAIDs experienced vomiting, compared to nearly 20% of those given opioids. Since nausea is already a common symptom during a stone episode, choosing a medication that worsens it is a real downside.
Common NSAIDs Used for Stone Pain
Several NSAIDs are effective. What your doctor recommends will depend on what’s available, how severe the pain is, and whether you can keep pills down.
- Ibuprofen is the most accessible option and is available over the counter. For kidney stone pain, higher doses (up to 800 mg three times daily) are sometimes used under medical guidance, though standard OTC dosing (400 mg every 6 to 8 hours) can help with milder episodes.
- Diclofenac is one of the most studied NSAIDs for renal colic, typically prescribed at 50 mg three times daily or 75 mg twice daily. It’s also available as a rectal suppository, which is useful if vomiting makes swallowing pills impossible.
- Naproxen at 500 mg twice daily provides longer-lasting relief per dose than ibuprofen, so it can help with overnight pain.
- Ketorolac is a powerful NSAID given by injection in emergency departments. It works fast and is often the first thing administered when you show up with acute stone pain.
If NSAIDs aren’t enough on their own, doctors may add acetaminophen (paracetamol) for additional relief. Acetaminophen won’t reduce inflammation, but it provides a separate pain-relief pathway without compounding NSAID side effects.
When NSAIDs Aren’t Safe
NSAIDs aren’t appropriate for everyone. If your kidney function is already reduced, these drugs can push it further. Current guidelines advise caution when kidney filtration rates fall between 30 and 60 mL/min, and avoiding NSAIDs entirely when rates drop below 30 mL/min. People with significant heart disease, a history of stomach ulcers, or those on blood thinners also need alternatives.
In those cases, doctors typically turn to opioids or acetaminophen as the primary pain control. Opioids are less ideal for the reasons above, but they’re a reasonable backup when anti-inflammatories are off the table. In rare cases of severe, unrelenting pain that doesn’t respond to standard medications, emergency physicians have used intravenous lidocaine (a numbing agent) as a rescue option. In one documented protocol, a patient’s pain dropped from severe to zero within five minutes of starting the infusion.
Medications That Help the Stone Pass
Pain management is only half the picture. The other goal is getting the stone out, and your odds depend heavily on size. Stones 3 mm or smaller pass on their own about 98% of the time. At 4 mm, that drops to 81%. A 5 mm stone passes roughly 65% of the time, and at 6 mm, only about 33%. Stones 6.5 mm or larger have a passage rate around 9%, which usually means a procedure is needed.
For stones in the 5 to 10 mm range where there’s still a realistic chance of passing naturally, doctors sometimes prescribe tamsulosin (0.4 mg daily), an alpha-blocker that relaxes the smooth muscle in the ureter to widen the passageway. This medication was widely recommended for years, but a large randomized trial found tamsulosin didn’t meaningfully improve passage rates compared to placebo: 50% passed with the drug versus 47% without it. Some urologists still prescribe it for larger stones (closer to 10 mm) in the lower ureter, where earlier studies showed a clearer benefit, but it’s no longer considered a sure thing.
Another option that’s been studied is nifedipine, a blood pressure medication that relaxes smooth muscle through a different mechanism. Head-to-head comparisons show tamsulosin produces higher stone passage rates than nifedipine, so when an expulsion medication is used, tamsulosin remains the preferred choice. Side effects of both are mild, mostly headache, dizziness, and occasional nausea.
One therapy that does not appear to help is adding an antispasmodic drug on top of NSAIDs. Clinical evidence shows no added pain reduction from combining antispasmodics with anti-inflammatories compared to anti-inflammatories alone.
Managing Pain at Home
If your stone is small enough to pass on its own and your doctor has sent you home, fluid intake is the single most important thing you can control. The NHS recommends drinking up to 3 liters (about 12 cups) of fluid per day until the stone clears. A good visual check: your urine should be pale yellow. If it’s dark, you’re not drinking enough. More fluid means more urine flow, which helps push the stone along and dilutes the compounds that caused it in the first place.
A heating pad or hot water bottle placed on your back or lower abdomen can ease the muscle spasm that accompanies stone movement. Warm baths work for the same reason. Keep your prescribed NSAID on a regular schedule rather than waiting for pain to peak before taking it. Staying ahead of the inflammation is far more effective than chasing it once it flares. Many people find the pain comes in intense waves lasting 20 to 60 minutes as the stone shifts positions, with relatively comfortable periods in between.
Strain your urine through a fine mesh filter or the strainer your doctor may have provided. Catching the stone lets your care team analyze its composition and recommend dietary changes to prevent future ones, which matters because roughly half of people who form one kidney stone will form another within five to ten years.